Illuminated sign



Sept. 10; 1935. v j JTGBEST .2;014,271

ILLUMINATED S IGN Filed Nov. 23, 1954 lNVE NTOR ATTORNEYS Patented Sept. 10, 1935 UNITED STATES PATENT OFFICE ILLUMINATED SIGN John Gordon Best, Toronto, Ontario, Canada, assignor to Varilux Limited, Toronto, Ontario, Canada, a company of Ontario Application November '23, 1934, Serial No. 754,405 In Canada March 20, 1934 10 Claims. (Cl. 40130) My invention relates to improvements in 'illurelatively to the background portion, depends minated signs in connection with which it may upon proper relative coloring of the indicia and be desired to obtain optical eifects of the characbackground, upon proper colors of the light reachter hereinafter described and relates also to a ing the sign, relatively to thecolors of the sign,

method of operating the same, this, application and upon proper frequency of recurrence of each 5 being a continuation in part of my application, color of light with which the sign is illuminated. Serial No. 716,759, filed March 22, 1934., j When the frequency of light color change is The primary object of the invention is to proslow, say of the order of one cycle per second, duce an optical illusion of movement or animathe eye is capable of accommodating itself to the tion in stationary portions of a sign or the like. g SO ha the Obse v e v the p Afurtherobject is to provide an effective methsion of a succession of color changes in both in-, 0d and means for producing the aforesaid optical dicia and background. For instance, using sign illusion. and light colors as in the last example, the ob- Various other objects and the advantages of server will receive discrete impressions of lumithe invention may be ascertained from the folnous red indicia on a dark or black bac r 15 lowing description and the accompanyin drawalternated with discrete impressions of dark or s. black indicia on a luminous green background.

In its broadest aspect, the invention comprises At o ha higher frequency of light 00101 illuminating a varicolored sign with light of varichange, the impression becomes blurred or jum- 0 ous colors in rapid succession so that the comd. the y being s d n a ptin to 216- plete color cycle and each individual color theredat ts t the higher sp d of color of IGCUIS' at high frequency, change and thus becoming incapable of clearly More specifically, the invention comprises asign registering discrete and Separate 00101 p having indicia portions and background portions s ns. At ill higher f qu n es of light color colored with colors, the distinguishing hues of Change, a new a entirely different efiect is D which are contrasting, and mutually exclusive, dllced p the y Instead Of discrete Q of the colors being preferably complementary; and confused color impressions at each light color means to illuminate the sign with light, the di change, a composite color impression is produced tinguishing hues of which are contrasting, mutuaccording to which the indicia and background ally exclusive and preferably complementary, in p rt ons of thes sn a h app a s ti u us y in such rapid sequence that persistence of vision is its O @0101 a the indicia pp to have a effective to the extent that retinal impressions of pulsating m v m t as of rn te nlar men the colors of the sign indicia and background, as and diminishmont and bodily movement in illuminated by light of corresponding color, are pa There s als more or l s st s p retained until the next recurring illumination of gefieet, that the indicia app to Stand Out the sign with light of that color so that the in,- ro backgrollhd- Due P p Ba y t0 dicia and background each appears continuously Psychological fi When the indicia are p in its own color irrespective of the color of light Sentations of natural Objects; the effect of P to which it is exposed. As exemplary of the fore- Eating and bodily movement appears to reproduce oi t indicia of the Sign may be colored red the natural movement of the object represented. 40 and th background colored green and the Sign .For example, representations of flames, flags, and illu i t by any suitable means with light, wheels appear respectively to flicker, flutter and ored alternately red and green. When the colors Otate- In the representation of a bird in flight, of the light are alternated at the above described the Wings appeal to beet up and down- When f eque the indicia appear continuously a the nature of the object represented by the indiluminous red and the background continuously $1065 not Suggest any direction of movement a luminous green, but the indicia appear to make the bodily movement appears to be in a generally the natural movements of the objects represented. lateral directionwhile the amplitude of p- It will be understood the invention is not limited parent bodily movement is Small, it s neve the- 50 to these colors in the si n and in the light as less v ry arresting to h gaze of a b d a 7 other colors may be used in either or both of is he pu sa i g mov a the Stereoscopic the sign and light. H effect. These optical effects are probablydue to The optical illusion of movement or animation the phenomena of irradiation and chromatic abof one portion of the'sign, preferably the indicia, erration. The pulsating efiect'is believed to be 55 due largely to irradiation and the effects of bodily movement and depth largely to chromatic aberration. Such irradiation gives the indicia the appearance of alternate enlargement and contraction which produces the aforesaid pulsating effect.

The necessary frequency of repetition of the color cycle, or frequency of color recurrence for the best effects, is between the minimum referred to above at which retinal impressions of the colors of the indicia and background as illuminated each by a corresponding color of light, begin to be retained until the next succeeding illumination of the sign with light of that color and a maximum at which persistence of vision becomes wholly effective and the image appears motionless, i. e., there is no appearance of movement or animation of the indicia or background. When only two colors of light are considered, the minimum frequency of color change in the illumination may be stated to be such that a retinal impression of each of the colors of the sign corresponding to the light colors, as illuminated by light of corresponding color, is retained for a" period of time equal to or greater than the duration of the immediatelysucceeding illumination of the sign with light of the other color. In other words, considering for example the case of a sign with red indicia on a green background and illuminated with light alternately red and green,

the frequency of color change in the light in such that the retinal impression of the red indicia as illuminated with red light is retained during the immediately succeeding illumination of the sign with green light, i. e., until the first recurrence of= illumination with red light. In the same way, the retinal impression of the green background as illuminated with green light is retained during j theop'timum frequencies for obtaining the said.

the immediately succeeding illumination of ,the sign with red light, i. e., until the first recurrence of illumination with green light.

The frequency of light change which produces the best effects within the range previously defined depends to some extent upon the colors of the indicia and background and the colors of the light. The nearer the colors approach to purity, the greater will be the intensity of effect. When the indicia represents an object, the most satisfactory frequency of color change will depend upon the nature of the object represented. For

example, the representation of sparks emanating from a spark plug will require a higher frequency of color change than the representation of flames arising from burning fuel. From the foregoing, it will be understood thereis an optimum frequency of color change for best results for each display, lying between the lower and upper limits already defined,.and that this optimum frequency can be approximately determined according to the foregoing general rules and then'exactly determined by varying the frequency.

In certain specific instances, I have found that animated efiect are between 6 and 9 cycles of color. change per second when the sign is receiving between 2 and 3 foot candles of incidental orthochromatic light, such as daylight. When the sign is exhibited in a dark room, the upper limit of optimum frequencies for obtaining said effect may be somewhat higher, for example about 12 cycles of color change per second. The frequency of color change at which retinal impressions of the sign as illuminated by one color of light begin to be retained until the next succeeding illumination with light of that color may be placed as lowas 4 cycles of color change per second with the above specified amount of incl-- dental light. The frequency of color change at which persistence of vision becomes substantially wholly effective and produces an image without 5 the aforesaid apparent pulsating and bodily movements may be placed .at approximately 17 cycles of color change per second. It is to be understood that either or both of, these upper and lower limits of color cycle frequency do not apply to every display since in some instances the range. necessarily may be narrowed at either or both ends by reason of the characteristics of the sign and/or of the light colors with which it is illuminated. The colors and color values of the light and of the different portions of thesign are prede- I termined, according to known laws governing the absorption and reflection of light of various wave lengths, with reference to one another such that one of the light colors, (for example red), relatively to the other or others (for example green or green and blue), is deficient in the predominating or distinguishing hue (for example green or blue) of one of the sign portions and, conversely, the color or colors of one of the sign portions, relatively to the color or colors of another or others of the sign portions, is deficient in the predominating or distinguishing hue of one of the light colors. By illuminating a sign colored in contrasting colors, preferably of complementary hues, with light colored in contrasting colors, preferably of complementary hues and preferably the same as the colors of the sign, and changing the colors of the light at frequencies within the defined range, I have provided a novel and efiective method of attracting the attention of observers and of increasing the advertising value of a display by imparting an optical effect of bodily 0 movement, animation and depth to the indicia portion of the sign. One advantage of my inven-' tion is that the sign may be effectively displayed with the striking results referred to even when it receives a relatively large amount of supplementary and preferably continuous light, such asdaylight. Indeed, I have found that the effect may sometimes be enhanced by providing an extra source of constant illumination of one or more colors.

T As herein used, the word. color is to be understood in a broad or general sense andnot as being limited to the indication of monochromatic or nearly'monochromatic color, i. e., pure color, which is herein designated by the term hue. Thus, the term color is inclusive of pure color and of blends of two or more pure colors. The term light means, according to context, the, light as it emanates from a source or as it is modified by passage through a screen or filter or by reflection or refraction.

The sign or display of my invention comprises essentially two portions which, for convenience of reference, have been termed indicia and background.

plurality of spaced locations in the sign and constitute one essential portion of the sign, the other essential portion being the background.

By background, I mean the portion or portions of the sign contrastingly colored, with respect to the indicia, in a non-corresponding and non-neutral color and preferably in a color complementary to the color of the indicia, contacting the whole or a major portion of the periphery of the indicia and extending outwardly therefrom an indeterminate distance. The background may but does not necessarily include the whole area of the sign apart from the indicia, since portions of the sign may be so colored as not to constitute background as above defined. Thus, the background may be merely an outlining or bordering of the indicia or may be the whole or a large portion of the field on which the indicia are displayed. In a sense and upon occasion, the indicia constitute background for adjacent portions of the sign which have been termed background.

The color of the indicia where it touches the background or the color of the background where it touches the indicia must be non-neutral and for the best efiect the colors of both the indicia and the background where they touch should be non-neutral and complementary. By non-neutral color, I mean color which has a distinguishing and predominating hue; in other words, color which partakes largely of the characteristics of a primary or pure color.

While the colors of the light are preferably as nearly as possible the same as the colors of the indicia and background, it will be understood it is practically impossible for them to be exactly the same since they are produced by difierent media. The word same, as used to indicate the relation of a sign color to a light color, is. therefore, to be understood as indicating that the predominating or distinguishing hue is the same in each.

Good efiects may be obtained by illuminating a sign with colors or" light which are not the same as those of the sign indicia and background but which may be described as corresponding. For example, a red and green sign may be illumirated with yellow or orange and blue light. For the purposes of this invention, purplish red, red, orange and yellow are-corresponding colors and green, blue green, blue, purple and violet are corresponding colors. Members of the above two groups cannot be paired indiscriminately but the selection must be governed by known laws of absorption and reflection of light.

In greater detail, the invention comprises the features and combinations of features disclosed in theprevious and following description and/or in the accompanying drawing, together with all such modifications, equivalents and substitutions as lie within the scope of the appended claims.

For simplicity of explanation, only the most elementary form of apparatus for putting the invention into practice will be described in detail. This elementary form of apparatus comprises, in combination with a sign as already described, a source of light and moving color screen interposed between the light source and the sign, said screen having differently colored transparent portions, the colors of which are preferably the same as the colors of the sign indicia and background.

In the accompanying drawing which illustrates one embodiment of the invention, but to the details of which the invention is not limited, as

modifications of detail and substitutions of equivalents may be made and are contemplated;

Fig. l is a sectional perspective view of the lighting apparatus and sign.

Fig. 2 is a plan view, the casing being in horizontal section to disclose the contained parts.

Fig. 3 is a vertical sectional view on the line 3-3 of Figure 2.

Referring more particularly to the drawing, ll designates a sign carrier of opaque or of trans- 10 lucent material, according to which side it is intended to be viewed from, upon which is painted, printed or otherwise affixed a sign l2 comprising essentially indicia i3 and background M. In the particular embodiment dealt with, the indicia 15 may be regarded as colored red and the background as colored green.

Associated with the sign is an illuminating device comprising a casing 85 having a light-egress slot or aperture 16 facing the sign and containing 20 a source of light H in register with the aperture i6 and the sign; a rotatably mounted, tubular, transparent color screen l8 surrounding the light source and arranged preferably axially parallel with the slot it; a motor as to effect rotation of 25 the screen about its axis and means 20 to operatively connect the motor and screen. The screen comprises a plurality of transparent differently colored portions, each extending from end to end of the screen and partially around the same, the 30 junction of adjacent colored portions being parallel with the length of the slot it. Two only of such differently colored portions, designated 28 and 22, are illustrated. The portion 29 may, for example, bered and the portion 22 may be green. The portions 2i and 22 may be of equal size circumferentially of the screen, as illustrated, or may be otherwise relatively proportioned. Likewise, the number of screen portions of each color may be increased if desired.

The screen is rotated about its axis at suitable angular speed by the motor and as each of the difierently colored portions comes into register between the source of light on the one hand, and the aperture i6 and sign on the other hand, the light passing from the source to the sign is colored alternately red and green. The red portion 28 will permit the red rays from the source ill to pass to the sign while intercepting or excluding the green rays and the green portion 22 59 will permit the green rays from the source ll to pass to the sign while intercepting or excluding the red rays. The suitable speed is that which will produce a frequency of color recurrence or color cycle recurrence as previously described.

Insofar as carrying out the method of my invention is concerned, there are numerous equivalents for the elementary apparatus previously described. A plurality of light sources, such as gas filled electric lamps giving initially difierent 001- 60 ors of light or a plurality of ordinary lamps giving so called white light and provided with differently colored bulbs or having colorless bulbs behind diiierently colored screens and associated with occulting shutters so synchronized that the 5' sign is illuminated by light from only one source at a time, are to be regarded as the equivalent of the lamp and screen hereinbeiore specifically described. Also, rotating or oscillating disc screens or reciprocating screens are to be regarded as equivalents of the tubular screen illustrated. Furthermore, a moving light source, or sources, with or without occulting shutter means, in association with a stationary color screen is to be regarded as equivalent of the arrangement illustrated. Regular variation in the speed of movement of a color screen or of a shutter is to be regarded as equivalent to making the colored portions of the screen of unequal size. While, in the embodiment illustrated, the relative positions of the light source, aperture l6 and sign are such that light passes in straight lines from the source to the sign, it is to be understood the invention is not limited to this relative positioning of the parts as other arrangements are contemplated. Various other equivalents for structure illustrated for carrying out the method of my invention will present themselves to persons skilled in the art.

Having thus described my invention, what I claim is:

1. The method of operating a sign, the indicia means of which are formed in shades of nonneutral color deficient in the color scheme of the background and the background of which is formed in shades of non-neutral color deficient in the color scheme of the indicia means, which method consists in projecting a beam of light toward said sign, interposing media in the path of said beam at a rate of speed within the speed range defined on one hand by the minimum speed at which a continuously retained retinal impression of the colors of said indicia and background begins and on the other hand by the speed at which persistency of vision becomes wholly effective, and said interposed media. acting successively to give to said beam colors first deficient in the color scheme of the indicia means and then deficient in the color scheme of the background.

2. In combination in an illuminated sign, a sign proper consisting of colored character indicia and a colored background, said indicia. being colored in colors deficient in said background and said background being colored in a color deficient in said indicia, and means for directing light onto the sign surface, said means comprising a light transmitting cylinder rotatably mounted and so positioned as to cast light upon said sign, and said cylinder having color zones some of which are deficient in the color scheme of the indicia means and some deficient in the color scheme of the background, a light source in said cylinder, means for rotating said cylinder to produce color alternations in the light as it is transmitted to the sign and at a speed which is not above the speed at which persistency of vision becomes operative and yet which is great enough for the eye to continuously'retain the impression of the color of both the sign proper and that of the background.

3. A sign device comprising, in combination, a sign including contacting indicia and background portions of different colors, the color of one of said portions being deficient in the distinguishing hue of the other portion which is deficient in the dis- -tinguishing hue of said first portion; and means for illuminating said sign with light of different colors in rapidly recurring sequences comprising a source of light, a light coloring device operatively related to said source and to the sign and including a plurality of diiferently colored portions, one of which, relatively to the remainder, is deficient in the distinguishing hue of one of said two contacting colored sign portions and another of which, relatively to the remainder, is deficient in the distinguishing hue of the other of said two contacting colored sign portions, and means for moving said light coloring device to position the differently colored portions thereof successively in the path of light passing from the source to the sign at a rate of speed within the speed range defined on the one hand by the minimum speed at which a continuously retained retinal impression of the colors of said indicia and background begins and on the other hand by the speed at which persistency of vision becomes wholly effective.

4. In combination in an illuminated sign, a sign 5 proper having indicia colored in a non-neutral color deficient in the distinguishing hue of the background and the background colored in a nonneutral color deficient in the color of the indicia, and means for illuminating said sign with light colored with a succession of colors to cause said indicia to appear animated, each of said light colors being deficient in the distinguishing hue of one of the sign colors, said means including a movable device for intermittently excluding light of each of said sign colors and said device being operable at a speed within the speed range defined on the one hand by the minimum speed at which a continuously retained retinal impression of the colors of said indicia and background begins and on the other hand by the speed at which persistency of vision produces a. motionless appearance of the sign.

5. In combination in an illuminated sign, a sign proper having indicia colored in a non-neutral color deficient in the distinguishing hue of the background and the background colored in a non-neutral color deficient in the color of the indicia, and means for illuminating said sign with light colored with a succession of colors to cause said indicia to appear animated, one of said light colors being deficient in the distinguishing hue of one of the sign colors, said means including a movable device for intermittently excluding light of said last-named light color, said device being operable at a speed within the speed range defined on the one hand by the minimum speed at which a continuously retained retinal impression of the color of said indicia begins and on the other hand by the speed at which persistency of vision pro- 40 duces a motionless appearance of the sign.

6. The method of operating a sign, the indicia means of which are formed in shades of nonneutral color deficient in the color scheme of the background and the background formed of shades of non-neutral color deficient in the color scheme of the indicia, which method consists in projecting a beam of light towards the sign, interposing a member intermittently in the path of said beam at a rate of speed within the speed range defined on the one hand by the minimum speed at which a continuously retained retinal impression of the colors of the indicia begins, and on the other'hand at the speed at which persistency of vision becomes wholly effective, said member acting .to intermittently exclude light of one of the sign colors.

7. The method of producing an optical illusion of movement in the stationary indicia of a sign the indicia portion of which is colored a non-neutral color deficient in the hue which distinguishes the background color from it and the background portion of which is colored in a non-neutral color deficient in the hue which distinguishes the indicia color from the background, which method comprises illuminating the sign with light of a plurality of colors, each of which colors relatively to the other is deficient in the distinguishing hue of one of the sign portions, and alternating the illumination caused by said light colors to produce changing color illumination of the sign, said alternations recurring intermittently at a speed within the speed range defined on the one hand by the minimum speed at which a continuously retained retinal impression of the color of the corresponding sign portion begins and the indicia and background of the sign appear continuously luminous each in its own color and on the other hand at the speed at which persistency of vision produces a motionless appearance of the sign.

8. The method of operating a sign the indicia portion of which is colored a non-neutral color deficient in the hue which distinguishes the background color from it and the background portion of which is colored in a non-neutral color deficient in the hue which distinguishes the indicia color from the background, which method comprises illuminating the said sign with light of a plurality of colors, each of which colors relatively to the other is deficient in the distinguishing hue of one of the sign portions, and alternating the illumination caused by said light colors to produce changing color illumination of the sign, said alternations recurring intermittently at a speed between 4 and 17 cycles per second whereby the indicia and background of the sign appear continuously luminous each in its own color but an optical illusion of movement in the stationary indicia of the sign is produce-d.

9. The method of producing an optical illusion of movement in the stationary indicia of a sign the indicia portion of which is colored a nonneutral color deficient in the hue which distinguishes the background color from it and the background portion of which is colored in a nonneutral color deficient in the hue which distinguishes the indicia color from the background, which method comprises illuminating the sign with light of a plurality of colors, each of which colors relatively to the other is deficient in the distinguishing hue of one of the sign portions, and intermittently and successively shutting off from said sign light of said light colors at a speed with- 5 in the speed range defined on the one hand by the minimum speed at which a continuously retained retinal impression of the color of the corresponding sign portion begins and the indicia and background of the sign appear continuously luminous each in its own color and on the other hand at the speed at which persistency of vision produces a motionless appearance of the sign.

10. The method of operating a sign the indicia portion of which is colored a non-neutral color deficient in the hue which distinguishes the back ground color from it and the background portion of which is colored in a non-neutral color deficient in the hue which distinguishes the indicia color from the background, which method comprises illuminating the said sign successively with light of a plurality of colors, each of which colors relatively to the other is deficient in the distinguishing hue of one of the sign portions, and causing the illumination by said light colors to recur intermittently at a speed between 4 and 17 cycles per second with intervals of non-illumination by said light colors whereby the indicia and background of the sign appear continuously luminous each in its own color but an opticalillusion of movement in the stationary indicia of the sign is produced.

JOHN GORDON BEST. 

